Engineers at NEC have developed a prototype optical disc drive that supports the new HD-DVD format and is also compatible with CD and DVD formats.

The drive is the latest to come out of NEC's research and development work supporting the HD-DVD format. HD-DVD discs are capable of storing several times more data than DVDs and are being positioned as the successor to DVD for storage of high-definition movies. The format's main backers are NEC, Toshiba and disc-maker Memory-Tech. It's also supported by the DVD Forum. The companies promise the first commercial HD-DVD players and drives in 2005.

The three-format drive supports playback of read-only (ROM) and rewritable versions (RW) of HD-DVD and read-only, write-once (R) and RW versions of CDs and DVDs.

"The base concept is the smooth transition from DVD to HD-DVD," said Hiroshi Inada, chief research manager of NEC's media and information research laboratories. "To realize such a concept, three-generation compatibility (of optical discs) is very important. For PC applications, this is a very important issue."

To produce the drive, engineers had to overcome several hurdles, said Toshiaki Iwanaga, principal researcher at NEC's optical recording technology center.

One of these hurdles is related to the optical head, which sits just above the disc and is one of the most crucial components in the device. Each of the three disc formats uses a laser that produces light of a different wavelength so the head must be compatible with all three types: 780 nanometer (nm) light used in CDs, 650 nm used in DVDs and 405 nm used in HD-DVD.

Working with engineers from Sanyo, which is also supporting HD-DVD, the team succeeded in producing an optical head that integrates support for all three formats.

NEC also had to integrate support for the different formats into a single chip. They succeeded in doing this and also included signal processing circuitry, said Iwanaga.

The new prototype marks a miniaturization of the drive technology. A year ago NEC showed a full height drive that supported HD-DVD and DVD only. The latest drive adds CD support to the mix and is half-height size, which makes it suitable for installation in the drive bays present in most desktop computers.

In a demonstration at NEC offices in Kawasaki, Japan, on Wednesday, the company showed flawless playback of Video CD, DVD and HD-DVD using the drive and a Windows XP-based personal computer.

NEC plans to offer the integrated chip starting in April and the drive starting in September next year as commercial products. The optical head will be sold by Sanyo, the NEC engineers said.

The prototype drive will be displayed at the upcoming International Consumer Electronics Show (CES) that is scheduled to take place at the Las Vegas Convention Center in Las Vegas from January 6 to January 9.

From DIGIT